1. Field of Invention
The present invention relates to an improved axle aperture plug for use in-line roller skates, and more particularly to a method of protecting the wheel bearings thereof using the same.
2. Brief Description of the Prior Art
In-line roller skates are well known in the art. The history of in-line roller skates is provided in the background of U.S. Pat. No. 5,048,848 which is incorporated herein by reference.
One type of in-line roller skate which have enjoyed enormous popularity over recent years is shown in FIGS. 1 through 4. As illustrated in FIG. 1, this in-line roller skate includes an elongated, light-weight elastic frame 1 to which a plurality of substantially identical in-line skate wheels 2A, 2B, 2C, and 2D are rotatably mounted. The frame carries a brake assembly 3 at the rear end thereof and is mounted to a boot 4 which provides protection and support to the foot and ankle of the skater.
A pair of front axle apertures 5A, 5B are formed at the front end of rails 1A and 1B of frame 1. A pair of rear axle apertures 6A, 6B are formed at the rear end of the side rails of the frame, respectively. Front axle apertures 5A, 5B confront one another and are coaxial in the axle associated with front wheel 2A. Rear axle apertures 6A, 6B confront one another and are coaxial with the axle associated with rear wheel. Two pairs of intermediate axle apertures 7A, 7B and 8A, 8B are formed in rails 1A and 1B, between the forward and rearward apertures. Apertures 7A, 7B and 8A and 8B confront each other and are coaxial with the wheel axles which mount wheels 2B and 2C, respectively. Each axle aperture in the frame has an oblong or oval configuration extending generally vertically and receives an axle plug aperture 9A in order to position the intermediate wheels in either an upper or lower position. When axle aperture plugs are inserted into the axle apertures in a particular orientation, all of the wheels are perfectly aligned with their axles disposed in a common plane parallel to the riding surface. As shown, each wheel 2A, 2B, 2C and 2D is substantially identical in construction, and is centered between side rails 1A and 1B on a common plane with each central axis of wheel rotation 10 being perpendicular to plane 11.
As illustrated in FIGS. 2 and 3, each wheel has an outer tire member 12 formed of resilient, yieldable polyurethane material which is molded about and closely encapsulates the outer portion of a central hub 13 which rotates about the central axis of the wheel. The hub is molded of plastic or other suitable synthetic material and has an outer substantially rigid ring 13A which is concentric with a smaller inner ring 13B. These substantially rigid rings are interconnected by a plurality of substantially rigid vanes 13C which are molded integrally with the hub. The inner ring has left and right bearing apertures 14A and 14B into which substantially identical left and right bearings 15 and 16 are received and frictionally retained.
As best shown in FIG. 3, bearings 15 and 16 each have a number of subcomponents, namely: a central axle bore 17, an inner race 18, an outer race 19, a flat annular-shaped outer face 20A covering ball bearing 21 and a flat annular shaped inner face 20B, in which the inner face is positioned in the hub adjacent bearing abutment 13D. Each wheel is provided with a bearing sleeve 22 having a raised central shoulder 22A, which abuts against the inner races of bearings 15 and 16 to space the bearings apart. The shoulder has a length substantially equal to the distance between the bearings when they are properly positioned in the bearing apertures of the hub. Cylindrical end sections 22B and 22C of the sleeve are of a suitable diameter and length to permit them to be inserted within and frictionally engage the inner races of the bearings so as to isolate the axle bore of the inner race from axle 23. Axle aperture plugs, bearing sleeves and bearings associated with each wheel are identical.
As illustrated in FIGS. 2 and 3, an axle aperture plug 9 is positioned on each side of the hub and is mateably received within each of the axle apertures of the frame. The axle aperture plug has a laterally extending, generally oblong lug 9A, whose outer periphery 9E is mateably, frictionally received and retained in an axle aperture of the frame. A collar 9C extending radially outwardly from the lug and having outer periphery 9B, bears against the inner surface 24 of the adjacent side rail.
As illustrated in FIG. 2, an axle bore 9D passes entirely through lug 9A and is sized to receive axle 23 therein. The axle bore is positioned eccentrically on the oblong lug and has a spacer 9F, in the form of raised annular rim, which encircles the axle bore and extends laterally along axle toward the hub, as shown in FIGS. 3 and 4. When an axle aperture is positioned in an axle aperture, the annular rim provides a washer-like mechanism which contacts the inner race 18 of the adjacent bearing and thereby assures necessary clearance between the outer race of the bearing and the side rails of the frame.
Each of the axles is substantially identical and formed by a bolt 23 having a wide, smoothly contoured head 23A and a threaded end 23B. A nut 25 with an integral lock nut mechanism is threadably received on bolt end 23B. The head and nut collectively comprise a clamping means on the axle by which the axle aperture plugs, the sleeve and the inner races of the bearings may be tightly retained on the skate frame. When the bolt and nut are tightened, the clamping effect forces the annular rims 9F of the axle aperture plugs against the inner race 18 of each bearing and the bearing against the ends of raised shoulder 22A of bearing sleeve 22. With this wheel assembly arrangement, the inner races of the bearings are securely retained, while the outer race of each bearing rotates freely about the axle to permit easy and fast rotation of the wheels.
Owing in large part to the major improvements in the design of the boot shell, skate frame and wheels in the above-described skate, in-line skating has become an increasingly popular outdoor sport. It is estimated that over six million people now use in-line skates in the United State of America alone. Typically, the areas with the highest degree of participation have been along boardwalks, all-purpose trails, or lake-front parks such as those commonly found in California, Chicago, Boston, New York and Florida. However, the sandy conditions associated with these sandy areas has consistently posed a major problem to the in-line skater. Specifically, the wheel bearings of prior art in-line skates are exposed to the elements, making them subject to contamination from particles of dirt and grit on the pavement, which are kicked up by the rotation of the wheels. These particles work their way into the inner parts of the wheel bearings, causing excessive wear, poor performance and early bearing failure.
In addition, the static electrical charge which builds up on the surface of the bearings during the rotation of the wheels, tends to draw some of the dirt particles toward the bearing and further contributes to the problem. The degree of damage caused by this problem can vary greatly depending upon the conditions to which the wheel bearings are exposed. However, the efficiency of the bearings can be substantially reduced after just a few hours of use, and it is not uncommon for one or more of the bearings to fail completely in shorter periods of time. In rental businesses which typically inventory as many as two hundred pairs of skates, the above-described problem becomes multiplied. Naturally, these businesses rely on the maintenance of their in-line skates to be in good working condition in order to protect their investment and minimize liability. Presently, replacement and maintenance of wheel bearings in in-line skates is expensive and time consuming.
Earlier approaches to solve the above-described problem were directed toward improved bearing design. Specifically, several different types of bearings having built-in bearing shields have been proposed. However, these prior art bearings have been generally ineffective in preventing dirt from entering the bearing.
Unable to adequately protect bearings from dirt and other environmental contaminates, more recent prior art efforts have been directed toward designing a user-serviceable bearing having a removable plastic or rubber shield which permits access to the internal parts of the bearing for periodic cleaning and lubrication. This prior art approach suffers from a number of significant shortcomings and drawbacks. In particular, the bearing cleaning process involves removing each of the wheels, then removing the bearings and then the bearing shield. The use of a toxic cleaning solvent is required to remove the dirt and old grease (or lubricant) inside the bearing housing. Then, each bearing must be re-packed with grease and the bearing seals replaced. Thereafter, the skate must be reassembled. Consequently, this prior art approach is both laborious and time intensive.
While prior art "bearing caps" of the type disclosed in U.S. Pat. Nos. 4,962,968, 4,511,182 and 4,408,803 have been proposed for skate bands and tandem-type roller skates, such prior art methods of protecting wheel bearings are generally inapplicable to in-line type roller skates.
Thus, there presently is a great need in the in-line roller skate art for an improved way of protecting wheel bearings from dirt and like contaminates.